Add two new PETS'15 papers.

references.bib

@@ -1,3 +1,25 @@
+@article{Ensafi2015a,
+	author = {Roya Ensafi and Philipp Winter and Abdullah Mueen and Jedidiah R. Crandall},
+	title = {Analyzing the {G}reat {F}irewall of {C}hina Over Space and Time},
+	journal = {Privacy Enhancing Technologies},
+	volume = {1},
+	number = {1},
+	publisher = {De Gruyter Open},
+	year = {2015},
+	url = {http://www.cs.kau.se/philwint/pdf/pets2015.pdf},
+}
+
+@article{Fifield2015a,
+	author = {David Fifield and Chang Lan and Rod Hynes and Percy Wegmann and Vern Paxson},
+	title = {Blocking-resistant communication through domain fronting},
+	journal = {Privacy Enhancing Technologies},
+	volume = {1},
+	number = {2},
+	publisher = {De Gruyter Open},
+	year = {2015},
+	url = {http://www.icir.org/vern/papers/meek-PETS-2015.pdf},
+}
+
 @inproceedings{Backes2009a,
 	author = {Michael Backes and Marek Hamerlik and Alessandro Linari and Matteo Maffei and Christos Tryfonopoulos and Gerhard Weikum},
 	title = {Anonymity and Censorship Resistance in Unstructured Overlay Networks},